ABSTRACT
Purpose: To report final results of a clinical trial of APBI using intensity modulated radiotherapy (IMRT) to deliver 27 Gy in 5 daily fractions following breast conserving surgery (BCS) prospectively designed to assess the efficacy and cosmetic outcomes of a oneweek, APBI regimen among women with early breast cancer. Material(s) and Method(s): Women >= 50 years, with lymph nodenegative, ER positive, HER-2 negative breast cancer or ductal carcinoma in situ (DCIS), <= 3cm diameter, following BCS with margins >= 2mm, and excellent or good baseline cosmesis received 27 Gy in 5 daily fractions to the seroma plus 1 cm CTV and 0.7 cm PTV margins. Clinical photographs, patient and provider cosmetic scores, breast fibrosis, telangiectasia and pain were collected prospectively, prior to RT and at 6 weeks, 1 and 2 years after RT. The primary endpoint was the proportion of women who retained Excellent or Good cosmesis at 2 years using the EORTC Cosmetic Rating System. Cosmetic failure was deterioration from Excellent or Good to Fair or Poor. A panel of 5 radiation oncologists independently assessed the cosmetic photographs. Secondary endpoints were rates and grades of breast fibrosis, telangiectasia, breast pain, ipsilateral breast tumour recurrence (IBRT), overall (OS), breast cancer-specific survival (BCSS) and subsequent mastectomy. Efficacy outcomes were assessed at clinic visits and by review of charts. ClinicalTrials.gov registration: NCT02681107. Result(s): A total of 298 patients were treated between April 25, 2016, and October 31, 2019. At a median follow-up of 48 months, the four-year OS was 98.5% (95% CI 96.1% - 99.5%) and BCSS was 99.7% (95% CI 97.6% - 99.9%). The four-year IBRT rate was 3.3% (95% CI 1.1% - 6.4%). There were 10 contralateral breast events for a four-year rate of 3.9% (95% CI 2.2% - 6.9%). There were 10 ipsilateral and six contralateral mastectomies. Two patients died of unrelated causes prior to two years;79 patients declined inclinic attendance due to COVID or competing comorbidities and 217 women had two-year cosmetic photographs and clinical assessments performed. Consensus of the photo-panel cosmesis at baseline was: Excellent: n=116 (53%), Good: n=102 (47%), Fair: n=1 (0.5%) and Poor: n=0. Consensus overall cosmesis at two years was: Excellent: n= 141 (65%), Good: n=78 (35%), Fair: n=0 and Poor: n=0. Most patients had either improved (n=168;77%) or no change (n=43;20%) in cosmesis at two years. No patient had cosmetic failure but 6 (3%) had a change from Excellent to Good at two years. Most patients reported either no (79%) or mild (21%) pain, with no moderate or severe pain. Two patients (0.9%) had Grade 2 fibrosis and five patients (2%) had visible telangiectasia that did not detract from overall cosmesis. Conclusion(s): APBI using 27 Gy in 5 fractions using a conformal IMRT technique, achieved excellent two-year cosmesis with minimal toxicity. The IBRT risk was comparable to the contralateral new breast cancer risk and to local recurrence rates of recently published early breast cancer trials. Copyright © 2022 Elsevier Ireland Ltd. This is an open access article under the CC-BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).
ABSTRACT
To report final results of a clinical trial of APBI using intensity modulated radiotherapy (IMRT) to deliver 27 Gy in 5 daily fractions following breast conserving surgery (BCS) prospectively designed to assess the efficacy and cosmetic outcomes of a 1-week, APBI regimen among women with early breast cancer. Women ≥ 50 years, with lymph node-negative, ER positive, HER-2 negative breast cancer or ductal carcinoma in situ (DCIS), ≤ 3cm diameter, following BCS with margins ≥ 2mm, and excellent or good baseline cosmesis received 27 Gy in 5 daily fractions to the seroma plus 1 cm CTV and 0.7 cm PTV margins. Clinical photographs, patient and provider cosmetic scores, breast fibrosis, telangiectasia and pain were collected prospectively, prior to RT and at 6 weeks, 1 and 2 years after RT. The primary endpoint was the proportion of women who retained Excellent or Good cosmesis at 2 years using the EORTC Cosmetic Rating System. Cosmetic failure was deterioration from Excellent or Good to Fair or Poor. A panel of 5 radiation oncologists independently assessed the cosmetic photographs. Secondary endpoints were rates and grades of breast fibrosis, telangiectasia, breast pain, ipsilateral breast tumor recurrence (IBRT), overall (OS), breast cancer-specific survival (BCSS) and subsequent mastectomy. Efficacy outcomes were assessed at clinic visits and by review of charts. ClinicalTrials.gov registration: NCT02681107. A total of 298 patients were treated between April 25, 2016, and October 31, 2019. At a median follow up of 48 months, the 4-year OS was 98.5% (95% CI 96.1% - 99.5%) and BCSS was 99.7% (95% CI 97.6% - 99.9%). The 4-year IBRT rate was 3.3% (95% CI 1.1% - 6.4%). There were 10 contralateral breast events for a 4-year rate of 3.9% (95% CI 2.2% - 6.9%). There were 10 ipsilateral and 6 contralateral mastectomies. Two patients died of unrelated causes prior to 2 years;79 patients declined in-clinic attendance due to COVID or competing comorbidities and 217 women had 2-year cosmetic photographs and clinical assessments performed. Consensus of the photo-panel cosmesis at baseline was: Excellent: n=116 (53%), Good: n=102 (47%), Fair: n=1 (0.5%) and Poor: n=0. Consensus overall cosmesis at 2 years was: Excellent: n= 141 (65%), Good: n=78 (35%), Fair: n=0 and Poor: n=0. Most patients had either improved (n=168;77%) or no change (n=43;20%) in cosmesis at 2-years. No patient had cosmetic failure but 6 (3%) had a change from Excellent to Good at 2 years. Most patients reported either no (79%) or mild (21%) pain, with no moderate or severe pain. Two patients (0.9%) had grade 2 fibrosis and 5 patients (2%) had visible telangiectasia that did not detract from overall cosmesis. APBI using 27 Gy in 5 fractions using a conformal IMRT technique, achieved excellent 2-year cosmesis with minimal toxicity. The IBRT risk was comparable to the contralateral new breast cancer risk and to local recurrence rates of recently published early breast cancer trials. [ FROM AUTHOR] Copyright of International Journal of Radiation Oncology, Biology, Physics is the property of Pergamon Press - An Imprint of Elsevier Science and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full . (Copyright applies to all s.)